Mechanical safety device for food processing appliance

ABSTRACT

Safety device for food processor in a bowl ( 2 ) closed by a cover ( 3 ), comprising a chute for introducing products into the working bowl, a pusher ( 5 ) slidably mounted in a pusher-guide ( 4 ) which is pivotally mounted onto the cover ( 3 ), and a set of rods connecting the pusher-guide ( 4 ) to the safety rod ( 2   a ) of the bowl ( 2 ).

FIELD OF THE INVENTION

[0001] The present invention relates to a safety device designed inparticular, but not exclusively, to food cutting apparatuses.

BACKGROUND OF THE INVENTION

[0002] These apparatuses which are well known in the field and arecalled vegetable cutters or meat/vegetable cutter units, comprise, amongothers, a motor unit enabling control and motorization of the cuttingtool and a device, commonly called vegetable cutter head, for feedingand cutting the products. The vegetable cutter head comprises a bowl,which is removable or integrated with the motor unit, of a suitableshape, enabling or not a continuous discharge of the treated products(closed bowl or open bowl); a cutting disk or tool located inside thebowl and which, as moved by the motor, makes the desired cut (slicing,grating, etc.); a cover; and, in case, a discharging disk.

[0003] The cover enables an introduction of the products to be processedby guiding them through one or a plurality of vertical tubes or chutes.It also provides a protecting function for the user by avoidingprojections of the processed product outside the bowl and, above all,avoiding the user to touch the moving disk.

[0004] Introduction of the food products within the machine is made bypositionning them in a suitable chute and by pushing them against thedisk with help of a pusher. In use, removing the pusher leaves the diskappearing through the chute. For large sized chutes, it is advisable, ifit is desired to protect the user from injury risks, to control workingof the motor to presence of a physical element obturating the chuteinlet.

[0005] It is known by FR-A-2 147 361 (VERDUN) to provide a mechanicalsafety of the presence of the cover on the bowl, this safety beingobtained by means of a sliding rod arranged according to a generatrix ofthe bowl and the lower part of which comes to bear, when the cover ispositionned, against a switch included within the base under action of acam which is carried by the cover. But this device does not permit toprovide a suitable chute safety, which leads to chutes having a greatheight and/or a limited cross-section.

[0006] A device for magnetically making this control function betweenthe pusher and the motor drive is known by U.S. Pat. No. 4, 821,968 anduses a set of magnets and flexible blade switches, or switches of theHall effect type. This device necessitates a transformation of theelectrical power and, moreover, the control by a magnetic field is moredelicate to design for the consideration of safety standard regulations.

[0007] Mechanical devices are already known which consist in operating apower circuit breaker when the position without risk of working of thechute pusher is reached. Such a device is described in U.S. Pat. No.4,674,690 in which the chute is surrounded by a sleeve, provided withmeans for activating the power circuit breaker, in which the pusher isenclosed.

[0008] The subject of the invention is to cope with all these problemsand to bring a solution to the control between the pusher which pushesthe products inserted in the chute and the drive of the motor. Thismechanical solution enables to use a chute having a great cross section.

[0009] According to the invention, the safety device for a foodprocessor with a rotating tool, comprising an electrical motor unit onwhich is mounted a bowl which is closed by a cover, the motor shaft,passing through the bottom of the bowl, being able to receive varioustools, the cover comprising a chute, a safety rod being arrangedaccording to a generatrix of the bowl and bearing on a switch arrangedin the feeding circuit of the motor unit, is characterized in that apusher is guided into translation in a pusher-guide, said pusher-guidebeing articulated at top of the chute and being mechanically connectedwith means for pushing on top of the safety rod, a small pivoting of thepusher-guide from its lower position causing stoppage of the motor.

[0010] The mechanical safety device for a food processor whichnecessitates or not an action from the user on the products during thecutting thereof, comprising a motor unit on which is mounted, in aremovable or not manner, a bowl which is closed by a cover, itselfremovable or not with respect to the bowl, provides a control of themotor to the position of one or a plurality of movable parts whichprevents access to the risking area. In the circumstances, a pivotingmovable part is formed by a pusher-guide, the pusher while slidinginside the pusher-guide permitting or not the same to pivot. Thenecessary obturation of the upper portion of the chute may be made,either by means of the pusher properly so called, or by thepusher-guide. The pusher is generally made by a handle of a reducedcross section, at the lower end of which is formed a plate having across section which is substantially equal to that of the chute.Obviously, the pusher handle freely slides in the pusher-guide. Theplate of the pusher can be extracted from the chute only when it isbrought above the same by a traction on the handle.

[0011] Pivoting the pusher-guide causes translation of a cover rod thelower end of which bears against the upper part of the safety rod of thebowl, pivoting can only be made when the pusher plate is brought intoabutment against the pusher-guide.

[0012] There is therefore made a control of the drive of a motor to theposition of a movable part which obturates access to the risking areaformed by the aperture of a chute having a great cross section.

[0013] According to another feature of the invention, the pusher-guidedrives a connecting rod by means of a first articulation, whichconnecting rod forcing, by means of the articulation of its second end,rotation of a crankshaft around a second pin which is fixed with respectto the cover, said crankshaft driving in its turn, by means of its firstarticulation which is common with said connecting rod, a first rod whichacts on the switch located in the motor unit through the second rod,guided into translation in the wall of the bowl, said second rod beingupwardly returned by a spring.

[0014] Mechanical devices are economical since they can directly act onan electric switch which supports currents compatible with those of themotor which are used. Therefore, the apparatus remains very simple andreliable and its manufacturing cost is more moderate than that of othersafety devices.

[0015] The pusher is connected to the cover of a vegetable cutter bymeans of an intermediary part which is called a pusher-guide. Thepusher-guide pivots around an horizontal pin which is positionned at theupper part of the chute and permits translation of the pusher.Therefore, when the pusher is in the chute, introduction of the productsto be processed is made by upwardly drawing the pusher up to the upperlevel of the chute, and then pivoting the pusher-guide in order to freethe inlet of the chute. When the chute is filled, the pressure which isexerted on the products is made by causing the pusher-guide to pivot sothat the pusher will be at the upper level of the chute, and thencausing the pusher to vertically descend inside the chute. Raising thepusher and then removing it enables to refill the chute. Closing theguide and descending the pusher enables to push the product against atool such as a cutting disk.

[0016] Controlling the motor operation to position of the pusher-guideenables to be sure that the motor does not operate when the pushersufficiently obturates the inlet of the chute. An assembly of rods,arranged between the cover and the pusher-guide, controls a safetyswitch which is set near the motor. Transmission of the translationmovement which activates the switch is provided by the safety rodlocated in the bowl of the vegetable cutter of the type as described inthe prementioned French patent. A return spring is used for returningthe rod in an upper position when the pusher-guide is not in a workingposition.

[0017] The inventive kinematics solves two joint problems connected withthis type of system:

[0018] When the pusher-guide is closed, the system must exert aresisting force to opening, which is just enough for permitting to raisethe pusher without driving the pusher-guide before the pusher iscompletely raised. This is required since, if not, an untimely rockingof the pusher-guide will produce a rubbing of the pusher in the chute,which is a minima detrimental to ergonomics, and is able to lead to acomplete blocking of the mechanism by buttressing. In the same time, theresistance force to opening must not be too high since it would then bea constraint for the user.

[0019] The system must also cause stoppage of the motor even when thepusher-guide is not rocked very much, i.e. much before access of thehand to the tool will be possible. It is therefore necessary that themechanism will produce a relatively important stroke of the rod which iscontained in the cover for a small angular clearance of thepusher-guide.

[0020] A small upwardly pivoting of the pusher-guide of the chute fromits lower position causes the motor to stop. Upon descending the pusherinside the chute, it is possible to trigger the motor while authorizingthe products to be processed to slightly pass beyond the upper level ofthe protected chute.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features and advantages of the invention will be revealedduring the following description of a particular embodiment given onlyas a non limitative example, with respect to the drawings which show:

[0022]FIG. 1, a perspective view of a complete machine;

[0023]FIG. 2, a perspective and half cross-sectionnal view broughttogether aside;

[0024]FIG. 3, a diagram of the mechanical device which provides,according to the invention, an action of the pusher on the rod of thebowl, when the pusher is completely descended;

[0025]FIG. 4, a drawing in cross section of the mechanism in thecondition described in FIG. 3;

[0026]FIG. 5, a diagram with the pusher being raised immediately whenthe device causes the motor to stop;

[0027]FIG. 6, a drawing in cross-section of the mechanism in thecondition described in FIG. 5;

[0028]FIG. 7, a diagram with the pusher completely open;

[0029]FIG. 8, a drawing in cross-section of the mechanism in thecondition described in FIG. 7.

MORE DETAILED DESCRIPTION

[0030] In all the figures, the same references designate the same items.

[0031]FIG. 1 shows all the machine, the mechanism which is necessary tokinematics being protected from smears by an assembly of suitable hoods.

[0032] In FIG. 1, the base 1 enclosing the motor (not shown) in used asa support for the bowl 1, closed by the cover 3, which comprises asmaller chute 3 a, and a greater chute 3 b, inside of which maypenetrate a pusher 5 which slides in a guide 4.

[0033]FIG. 2 shows thanks to the cross-section of the vegetable cutterhead, the smaller chute 3 a which does not necessitate any safety deviceand the greater chute 3 b the use of which is protected by the safetysystem of the invention. The head is shown in the position for fillingthe greater chute. In FIG. 2, a safety switch 1 a is arranged inside thebase 1, beneath a safety rod 2 a which is slidingly mounted according toa generatrix of the bowl 2 and on which the rod 6 of the cover 3 willact.

[0034] FIGS. 3 to 8 are diagrams and drawings enabling to explain theworking of the mechanism designed to transform the pivoting movement ofthe pusher-guide into a vertical translation movement of the rod whichis mounted in a wall of the bowl, upon pivoting the pusher-guide, afterhaving brought the pusher at the upper level of the chute.

[0035] The pusher-guide 4 is articulated around a pin 4 a which is fixedwith respect to the cover 3. The pusher-guide 4 carries also a pin 8 bon which is articulated the connecting rod 8. The second end of theconnecting rod 8 is articulated onto one end 7 b of a crankshaft 7 thesecond end 7 a of which is articulated in a fixed point 7 a of the cover3. On the end 7 b is also articulated one end of the rod 6 the secondend of which is guided in an aperture 3 c of the cover and comes to bearon the safety rod 2 a which is slidably mounted in the bowl.

[0036] Pivoting the pusher-guide 4 moves the pin 8 b, the pin 7 a beingfixed, and the distances between 7 a and 7 b and respectively 7 b and 8b being constant, the point 7 b will then describe an arc of a circlearound 7 a. The upper end of the rod 6, which is fixed at 7 b, followsthe same movement. It is moreover guided into translation by means ofthe aperture 3 c made in the cover, which results in vertically movingthe lower end 6 a of this rod. Since the spring 2 b ensures a contactbetween the upper part of the rod 2 a and the lower face of the rod 6,the bowl safety rod 2 a is vertically moved in the same way, up to endof clearance of the pusher-guide 4 in either direction.

[0037] In FIGS. 3 and 4, the pusher-guide is closed and the pusher iscompletely descended in the chute 3 b. FIGS. 3 and 4 show the positionof the assembly when the user has pushed the products through the chute3 b. The pusher 5 is in its lower position and the rod 6 pushes onto thetop of the safety rod 2 a which itself closes the switch 1 a. Forreturning to its opening position, it is necessary to raise the pusher5, and then to pivot the pusher-guide 4 in the clockwise direction.

[0038] The diagram of FIG. 3 shows how the device will exert, on thepusher-guide, the above described resisting force to opening. This isobtained by the fact that the crankshaft 7, which has slightly rotatedbeyond the vertical position, in the movement for closing thepusher-guide, will exert, by means of its pin 7 b, a traction on theconnecting rod 8 which, in its turn, will tend to maintain thepusher-guide 4 closed by its connection 8 b, under action of the spring2 b as transmitted to the rod 6 by means of the rod 2 a.

[0039] In FIGS. 5 and 6, the pusher 5 has been raised at maximum in thechute 3 b and then the pusher-guide 4 has pivoted in an intermediaryposition in the clockwise direction. This position is that of the systemupon triggering the safety switch 1 a, and clearly shows that access ofthe hand to the tool is prevented when a command to stop the motor isgiven.

[0040]FIGS. 5 and 6 specify the position of the system when the rod 6 issufficiently raised so that the rod 2 a will free the switch 1 a, whichresults in stopping the motor. In the opposing position for closing thepusher, this is also practically the position from which it is possibleto re-start the motor. This feature of the device enables to fill at100% the volume of the chute 3 b with products to be processed andmaximized therefore performances of the apparatus.

[0041]FIGS. 7 and 8 show the device in its completely open position withthe pusher completely raised, showing a direct access to all the surfaceof the chute.

[0042] In FIGS. 7 and 8, the pusher-guide 4 has continued to rotate inthe clockwise direction for reaching its maximal opening position whichpermits the pusher 5 to completely free the aperture of the chute 3 b inorder to very easily refill it with products to be processed.

[0043] Since the pusher-guide is articulated on a pin 4, contact of therod 2 b on the switch 1 a is made when the lower surface of thepusher-guide 4 forms an angle of about 10° with horizontal in theclockwise direction and is interrupted when the lower surface of thepusher-guide forms an angle of about 11° in the anti-clockwisedirection. This means that a small pivoting of the pusher-guide willinterrupt the contact between the rod 2 a and the switch 1 a, which willstop the motor which is no more supplied in electrical power. In thedirection for obturating the chute, a slightly untimely closing enablesto operate when food, for example vegetables having an irregular shape,will pass beyond the inlet level of the chute. Thus, the same can beloaded at its maximal capacity.

[0044] A significant advantage of the inventive safety system is thepossibility to use a cylindrical chute, or a chute having another shapeof a surface equal to that of the pusher and of a height equal to thestroke of the pusher. Thus the worked volume is optimal.

[0045] Another advantage of the kinematics as retained is the safety inuse of a chute the products of which may slightly pass beyond it, whichavoids to calibrate the products, thus increasing greatly the easinessof use. Simplicity of the mechanics which forms this safety system, withrespect to the prior art, enables to clearly show, in addition to thealready mentioned advantages, an increased reliability.

[0046] It is obvious that various variants may be brought into effect,in particular by substitution of equivalent technical means, withouttherefor departing from the scope of the invention.

1. Safety device for food processor with a rotating tool, comprising anelectrical motor unit (1) on which is mounted a bowl (2) which is closedby a cover (3), the motor shaft, passing inside the bowl, being able toreceive various tools, the cover (3) comprising a chute (3 b) forintroducing the food, a safety rod (2 a) being arranged according to ageneratrix of the bowl (2) and bearing on a switch (1 a) arranged in thefeeding circuit of the motor unit, characterized in that a pusher (5) isguided into translation in the chute (3 b) by a pusher-guide (4), saidpusher-guide, being articulated at top of the chute (3 b) and beingmechanically connected with means for pushing on top of the safety rod(2 a), the mechanism causing the motor to stop for a small angularclearance of the pusher-guide (4) in the clockwise direction.
 2. Safetydevice according to claim 1, characterized in that the chute (3 b) has acylindrical general shape, the pusher (4) being of a surfacesubstantially equal to the cross section of the chute (3 b).
 3. Deviceaccording to claim 1, characterized in that the pusher-guide (4) drivesa connecting rod (8) by means of an articulation (8 b), which connectingrod (8) forces, by means of the articulation (8 a) of its second end, arotation of a crankshaft (7) around a pin (7 a) which is fixed withrespect to the cover (3), said crankshaft driving in its turn, by meansof its articulation (8 a) which is common with the connecting rod (8), arod (6) which acts on the switch (1 a) located in the motor unit (1)through the rod (2 a), guided into translation in the wall of the bowl(2), the rod (2 a) being upwardly returned by a spring (2 b).
 4. Deviceaccording to claim 1, characterized in that, upon closing thepusher-guide (4) on the chute (3 b), the motor is triggered when theinclination angle is of some degrees before the same will take itshorizontal position, by authorizing the products to be processed to passbeyond the upper level of the protected chute (3 b).
 5. Device accordingto claim 1, characterized in that the mechanics exert a resisting forceto displacement of the pusher (5) in the chute which enables a slide ofthe pusher (5) in the pusher-guide (4) without causing said pusher-guideto pivot.
 6. Device according to claim 1, characterized in that, sincethe pusher-guide is articulated onto a pin (4 a), the contact of the rod(2 a) on the switch (1 a) is established when the lower surface of thepusher-guide (4) forms an angle of about 10° with the horizontal in theclockwise direction and is interrupted when the lower surface of thepusher-guide forms an angle of about 11° in the anti-clockwisedirection.